Previous research has suggested that protein is the most satiating macronutrient; however some experiments have found no difference in satiating efficiency of protein and carbohydrate during short intervals after consumption. There is also evidence that the satiating effects of carbohydrate are minimal when in a beverage rather than solid context. To evaluate whether protein-based satiety was evident in a drink context, and clarify further effects of preload time on satiety, the present study compared iso-energetic dairy fruit drink preloads ( approximately 1250 kJ), differing in macronutrient composition and consumed at two time intervals in the morning. Using a counterbalanced within-subjects design, 18 unrestrained lean male volunteers consumed 300 ml of carbohydrate-enriched (CHO), protein-enriched and low-energy control (327 kJ) dairy fruit drinks, 120 min and 30 min before an ad libitum lunch. Significantly less energy was consumed at lunch after the protein (3234 kJ) compared to the control (3468 kJ, p<0.05) and CHO preloads (3588 kJ, p<0.05). However, this was not sufficient to show complete energy compensation. Preload time of consumption did not impact upon any measures. Only satiety ratings at the beginning of lunch varied significantly by preload type, reflecting differences in test meal intake. These findings are consistent with previous research that protein is more satiating than carbohydrate. The roles of sensory and hedonic characteristics are discussed.

Background: There are consistent, evidence-based global public health recommendations to reduce intakes of free sugars. However, the corresponding evidence for recommending reduced exposure to sweetness is less clear. Objective: Our aim was to identify and review the published evidence investigating the impact of dietary exposure to sweet-tasting foods or beverages on the subsequent generalized acceptance, preference, or choice of sweet foods and beverages in the diet. Design: Systematic searches were conducted to identify all studies testing relations of variation in exposure to sweetness through foods and beverages with subsequent variation in the generalized acceptance, preference, or choice of sweetened foods or beverages, in humans aged >6 mo. Results: Twenty-one studies met our inclusion criteria, comprising 7 population cohort studies involving 2320 children and 14 controlled trials involving 1113 individuals. These studies were heterogeneous in study design, population, exposure, and outcomes measured, and few were explicitly designed to address our research question. The findings from these were inconsistent. We found equivocal evidence from population cohort studies. The evidence from controlled studies suggests that a higher sweet taste exposure tends to lead to reduced preferences for sweetness in the shorter term, but very limited effects were found in the longer term. Conclusions: A small and heterogeneous body of research currently has considered the impact of varying exposure to sweet taste on subsequent generalized sweet taste preferences, and this evidence is equivocal regarding the presence and possible direction of a relation. Future work should focus on adequately powered studies with wellcharacterized exposures of sufficient duration. This review was registered with PROSPERO as CRD42016051840, 24 November 2016. Am J Clin Nutr 2018107:405-419.

Adult playfulness is a personality trait that enables people to frame or reframe everyday situations in such a way that they experience them as entertaining, intellectually stimulating, or personally interesting. Earlier research supports the notion that playfulness is associated with the pursuit of an active way of life. While playful children are typically described as being active, only limited knowledge exists on whether playfulness in adults is also associated with physical activity. Additionally, existing literature has not considered different facets of playfulness, but only global playfulness. Therefore, we employed a multifaceted model that allows distinguishing among Other-directed, Lighthearted, Intellectual, and Whimsical playfulness. For narrowing this gap in the literature, we conducted two studies addressing the associations of playfulness with health, activity, and fitness. The main aim of Study 1 was a comparison of self-ratings (N = 529) and ratings from knowledgeable others (N = 141). We tested the association of self- and peer-reported playfulness with self- and peer-reported physical activity, fitness, and health behaviors. There was a good convergence of playfulness among self- and peer-ratings (between r = 0.46 and 0.55, all p < 0.001). Data show that both self- and peer-ratings are differentially associated with physical activity, fitness, and health behaviors. For example, self-rated playfulness shared 3% of the variance with self-rated physical fitness and 14% with the pursuit of an active way of life. Study 2 provides data on the association between self-rated playfulness and objective measures of physical fitness (i.e., hand and forearm strength, lower body muscular strength and endurance, cardio-respiratory fitness, back and leg flexibility, and hand and finger dexterity) using a sample of N = 67 adults. Self-rated playfulness was associated with lower baseline and activity (climbing stairs) heart rate and faster recovery heart rate (correlation coefficients were between −0.19 and −0.24 for global playfulness). Overall, Study 2 supported the findings of Study 1 by showing positive associations of playfulness with objective indicators of physical fitness (primarily cardio-respiratory fitness). The findings represent a starting point for future studies on the relationships between playfulness, and health, activity, and physical fitness.

Previous research suggests that increasing beverage protein content enhances subsequent satiety, but whether this effect is entirely attributable to post-ingestive effects of protein or is partly caused by the distinct sensory characteristics imparted by the presence of protein remains unclear. To try and discriminate nutritive from sensory effects of added protein, we contrasted effects of three higher-energy (about 1·2 MJ) and one lower-energy (LE: 0·35 MJ) drink preloads on subsequent appetite and lunch intake. Two higher-energy drinks had 44 % of energy from protein, one with the sensory characteristics of a juice drink (HP2, low-sensory protein) and the second a thicker and creamier (HPþ, high-sensory protein) drink. The high-carbohydrate preload (HCþ , high-sensory carbohydrate) was matched for thickness and creaminess to the HPþ drink. Participants (healthy male volunteers, n 26) consumed significantly less at lunch after the HPþ(566 g) and HCþ (572 g) than after HP2 (623 g) and LE (668 g) drinks, although the compensation for drink energy accounted for only 50 % of extra energy at best. Appetite ratings indicated that participants felt significantly less hungry and more full immediately before lunch in HPþ and HCþ groups compared with LE, with HP2 being intermediate. The finding that protein generated stronger satiety in the context of a thicker creamier drink (HPþ but not HP2) and that an isoenergetic carbohydrate drink (HCþ ), matched in thickness and creaminess to the HPþ drink, generated the same pattern of satiety as HPþ, both suggest an important role for these sensory cues in the development of protein-based satiety.Key words: Protein: Satiety: Viscosity: Thickness It has been widely reported that meals with a higher proportion of energy as protein are more satiating than isoenergetic meals lower in protein content, both in acute tests of satiety using short-term measures of rated appetite and/or intake (1 -10) and longer-term studies on manipulated protein content of the diet (11 -14) . However, there remains some uncertainty about the mechanisms underlying the enhanced satiating efficiency of protein-based foods and drinks. Although there is clear evidence that protein ingestion results in a different profile of satiety-related hormonal signals compared with other macronutrients (15 -17) that have been interpreted as the basis of protein-based satiety (18) , a confounding issue in interpretation of many short-term studies of protein-based satiety is the difficulty in fully disguising the addition of protein. This often results in orosensory differences between protein and control conditions, which could also contribute to the behavioural effects of these foods and drinks. It is well established that orosensory cues are an important component of short-term satiety. For example, high-energy preloads have been shown to be more satiating when ingested by the participant than when infused directly into the stomach or intestine (19) . Observations like this add weight to the satiety-cascade ...

Children's reports about their play in middle childhood and the emotions they associate with play have received limited research attention. Using focus groups, this study asked 38 children in the UK about what, where and with whom they played. They were also asked how play made them feel. Children reported a wide range of play behaviours, with outdoor and traditional games being just as prominently mentioned as play with electronic devices. The emotional importance of play in middle childhood was apparent, with children associating play with strong positive emotions, and not being able to play with negative emotions and anxiety.